INVESTIGATION OF THE BOW SPRING CENTRALIZER WITH (BHA) IN DIRECTIONAL WELLS

Bottom hole assemblies (BHA)s calculation methods with the bow spring eentralizer is proposed in this paper, that allows detecting an effect of the place of installation and stiffness of centralizer arms on the bit deviation force when drilling directional and horizontal wells[4,6|. The arm of the bow spring centralizer is regarded as the single leaf spring possessing certain stiffness. It was shown that depending on the place of installation the bow spring centralizer can be successfully used when the inclination angle equal zero, lower and higher than zero (α , 0, 0) for drilling directional and horizontal wells. Advantage of bow spring centralizers comparing to conventional ones is that besides non- oriented control of inclination angle they allow stabilizing azimuth, as they align the bit in horizontal plane and prevent centralizer reeling up against the sidewall of the well. Also, using centralizers with the arms and different stiffness make possible to control inclination angle without pulling the bit to the surface, by rotation the centralizer and its orientation